<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <p class="text">hello world</p>
  <script>
    // var p = document.getElementById('text')
    // p.style.color = 'red'
  var a = 10    // var、 a、 =、 2

  function foo(a){
    var b = 2
    function bar(){
      console.log(5);
    }
    var c =3
  }
  foo(1)
  console.log(a, b, c);
  
  // ['var', 'a', '=', '2',['function', 'foo', '...']]  //
  </script>
</body>
</html>